But still, are we into something? Let's see how this way of thinking works for another particle, namely the photon, light.
Physics says that photons have no mass when they are at rest. They do not buzz around in clusters like the quarks but fly away freely and alone at the speed of light.
But the moment they move, the same thing happens as it did with the quarks. The photon gains mass. For example, photons from the Sun can push large solar sails that
set space probes in motion.
Kinetic energy is experienced as mass with force sufficient to move space probes, ultimately also mountains, even if what is moving in itself is massless!
The logical interpretation is that photons are elementary, i.e. not composed of anything else, because they have zero resting mass. The moment photons move, they get plenty.
Can it be that simple? That mass is simply the «feel» of movement, the experience of kinetic energy?
That mass is not mysterious and unique in itself but a property of something else, the qualia of motion?
Do we have more clues pointing in the same direction?